Pseudo-geosynchronous communications in satellite platforms

ABSTRACT

Systems, methods, and software described herein provide enhancements for orbital satellite platform. In one example, a satellite system includes satellite devices in low-earth orbit (LEO) configured to establish a pseudo-geosynchronous configuration corresponding to a ground communication system by at least transferring instructions for traffic routing from outgoing satellite devices leaving the pseudo-geosynchronous window for receipt by target satellite devices entering the pseudo-geosynchronous window. During passage within the pseudo-geosynchronous window, the target satellite devices are each configured to route communications received in the target satellite devices from ones of the satellite devices through the ground communication system in accordance with the instructions for traffic routing.

RELATED APPLICATIONS

This application is a continuation of, and claims priority to, U.S.patent application Ser. No. 15/653,718, entitled “PSEUDO-GEOSYNCHRONOUSCONFIGURATIONS IN SATELLITE PLATFORMS,” and filed Jul. 19, 2017, nowU.S. Pat. No. 9,960,837.

BACKGROUND

Satellites can be deployed into orbit to provide various space-basedoperations, such as military and civilian observation operations,communications operations, navigation operations, weather operations,and research operations. Satellites can include various sensors andcommunication equipment that are used to perform desired tasks. However,most satellites deployed in orbit comprise singular entities that areexpensive to create and launch into orbit, especially for organizationsthat may not require the use of an entire satellite with a large numberof sensors, or may not require continuous operations on the satellite.As a result, organizations may avoid the use of satellites, limiting theuse of promising satellite technology.

OVERVIEW

Systems, methods, and software described herein provide enhancements fororbital satellite platform. In one example, a satellite system includessatellite devices in low-earth orbit (LEO) configured to establish apseudo-geosynchronous configuration corresponding to a groundcommunication system by at least transferring instructions for trafficrouting from outgoing satellite devices leaving thepseudo-geosynchronous window for receipt by target satellite devicesentering the pseudo-geosynchronous window. During passage within thepseudo-geosynchronous window, the target satellite devices are eachconfigured to route communications received in the target satellitedevices from ones of the satellite devices through the groundcommunication system in accordance with the instructions for trafficrouting.

This Overview is provided to introduce a selection of concepts in asimplified form that are further described below in the TechnicalDisclosure. It should be understood that this Overview is not intendedto identify key features or essential features of the claimed subjectmatter, nor should it be used to limit the scope of the claimed subjectmatter.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the disclosure can be better understood with referenceto the following drawings. While several implementations are describedin connection with these drawings, the disclosure is not limited to theimplementations disclosed herein. On the contrary, the intent is tocover all alternatives, modifications, and equivalents.

FIG. 1 illustrates a satellite environment according to animplementation.

FIG. 2 illustrates an expanded view of a satellite capable of providinga platform for virtual nodes according to an implementation.

FIG. 3 illustrates operations of layered deployment of satellitesaccording to an implementation.

FIG. 4 illustrates a satellite environment according to animplementation.

FIG. 5 illustrates a satellite environment according to animplementation.

FIG. 6 illustrates operations of pseudo-geosynchronous deployment ofsatellites according to an implementation.

FIG. 7 illustrates a satellite environment according to animplementation.

FIG. 8 illustrates a satellite environment according to animplementation.

FIG. 9 illustrates operations of specialized role deployment ofsatellites according to an implementation.

FIG. 10 illustrates a satellite environment according to animplementation.

FIG. 11 illustrates a satellite environment according to animplementation.

FIG. 12 illustrates peering satellite operations according to animplementation.

FIG. 13 illustrates a satellite computing system to provide avirtualized satellite application platform according to animplementation.

DETAILED DESCRIPTION

The various examples disclosed herein provide enhancements for satellitehardware and software technology. For example, a cluster of satellitedevices can be deployed into orbit using a launch system. Thesesatellite devices can comprise general-purpose satellite devices, suchas CubeSat devices configured with processing systems, storage systems,and communication systems. These satellite devices can also havespecialized roles which can be defined according to provisioned hardwareor software elements, or can be associated with a particular set ofapplications deployed to the associated satellites. In some examples, amulti-layered orbital arrangement of a plurality of satellite devices isprovided. This multi-layered arrangement provides for enhancedcommunications, imaging coverage, redundancy, and fault-tolerance, amongother operations. Pseudo-geosynchronous windows can be established bythe satellite platforms using passage through a virtual orlogically-defined window to trigger specialized operations of thesatellite devices. Further examples include storage area networks (SAN)configurations where one or more satellite devices can include storagesystems used for deployment of virtual machine images, containers,differential state information, or other state information related tothe execution of virtual nodes by one or more peer satellite devices ofthe cluster.

The examples disclosed herein provide systems and methods for deployingsoftware applications in an orbiting satellite platform, wherein each ofthe software applications executes as a virtual node that can shareresources with one or more other applications deployed to the samesatellite device. These virtual nodes may comprise full operating systemvirtual machines in some examples, and may further include virtualcontainers. These containers may include Docker containers, Linuxcontainers, jails, or another similar type of virtual containment node,which can provide an efficient management of resources from a hostsystem. The resources used by the containers may include kernelresources from the host computing system, and may further includerepositories and other approved resources that can be shared with othercontainers or processes executing on the host. However, althoughresources may be shared between the containers on a host satellitedevice, the containers are provisioned to have private access to theoperating system with their own identifier space, file system structure,and network interfaces.

In the present example, to provide the satellite platform, a pluralityof satellite devices may be deployed, referred herein as satellites orsatellite devices. Organizations may generate applications and deploythe applications to the satellite devices to perform desired operations.These operations may include military and civilian observationoperations, communications operations, navigation operations, weatheroperations, and research operations. Applications may be deployed in oneor more satellite devices of the orbiting satellite platform. In someimplementations, the application may be provided to each of the one ormore satellite devices using a ground control system or groundcommunication system as an uplink to the one or more satellite devices.In other implementations, a single uplink may be made to a satellitedevice in the platform, wherein the satellite device is configured todistribute the application to other desired satellite devices in theplatform. Once deployed in the environment, the application may executeon the assigned satellite devices.

In some implementations, the satellite devices of the satellite platformmay each exchange state information with one or more other satellitesand the ground control system for the platform. This state informationmay include current operational state information for each of theapplications, such as the tasks or processes that are operating, and mayfurther exchange data generated at least partially from the sensors ofthe satellite. This data may be used in a peer group, wherein a firstsatellite may identify a first set of data, and provide the data to asecond satellite. The second satellite may then identify second dataand, process the first and second data as defined by the application.This operation may be used, as an example, in imaging operations,wherein a first satellite may take images of an object over a firstperiod of time, and provide data for the images to the second satellite.The second satellite may take subsequent images and use the data for thefirst images and the subsequent images to make a determination about anobject. Although this is one example, it should be understood that otheroperations may use peer sharing of state data to identifycharacteristics about measured data from the satellite sensors.

As a first example satellite platform, FIG. 1 is shown. FIG. 1illustrates a satellite environment 100 according to an implementation.Satellite environment 100 includes satellite cluster 101 with satellites111-116 arranged in upper later 110, and satellites 121-126 arranged inlower layer 120. FIG. 1 also includes ground control system 170 andEarth 190. Satellites 111-116 form a first orbital layer and include acirculating network arrangement for exchanging network communicationsamong members of upper layer 110. Satellites 121-126 form a secondorbital layer and include a circulating network arrangement forexchanging network communications among members of lower layer 120. The‘height’ of the layers can comprise an orbital distance from the surfaceof Earth 190, among other distance metrics that can differentiatelayers. Satellites 111-114 communicate over wireless network links141-142, and satellites 121-124 communicate over wireless network links143-144. In some examples, a further wireless network link 145 isincluded to couple communications among layers 110 and 120. Groundcontrol system 170 communicates with satellites 111 121 using associatedwireless communication links 151-152.

As described herein, a plurality of satellites 111-116 and 121-126 maybe launched and deployed as an orbiting platform for a plurality ofdifferent software application payloads. Ground control system 170 mayinitiate an uplink with one or more of the satellites to providesoftware application payloads to the satellites, as well as update anyscheduling information for the satellites. Once uploaded to the desiredsatellites, the software application payloads may begin execution. Insome implementations, the uplink from ground control system 170 may besolely responsible for providing the applications to the requiredsatellites. In other implementations, ground control system 170 maysupply an application to a first set of satellites, which may thendistribute the application to one or more other satellites of thesatellite platform. For example, ground control system 170 may provide afirst application to satellite device 111 over link 151, whereinsatellite device 111 may, in turn supply the application to othersatellites in a peer group. In particular, satellite device 111 mayprovide the application to satellite 112 that is in the same peer group,permitting satellite 112 to provide operations of the applicationwithout directly receiving the communication from ground control system170. Additionally, similar to providing the initial configuration to thesatellites, ground control system 170 may further be used to supplyupdates to each of the applications operating in the satellite platform,and may further update any scheduling information on each of thesatellites.

FIG. 2 is a flow diagram illustrating example operations of the elementsof FIG. 1. In FIG. 2, satellite cluster 101 establishes (201) a firstsubset of satellite devices within in a first orbital layer 110,establishes (202) a second subset of satellite devices within in asecond orbital layer 120. In FIG. 1, the second orbital layer comprisesan orbit 103 with a second orbital distance less than an orbit 102 ofthe first orbital layer, although different distances can be employed.As mentioned above layer 110 includes satellite devices 111-116 andlayer 120 comprises satellite devices 121-126. It should be understoodthat a different number of satellites can instead be employed.

A communication network is formed among members of layer 110 and amongmembers of layer 120, which may be a subset of the total number ofsatellite devices of a layer. In FIG. 1, a first communication networkis formed among satellite devices 111-114 and a second communicationnetwork is formed among satellite devices 121-124. A third communicationnetwork can be formed among members of both layers in some examples, orthe first and second communication networks can be merged into a singlenetwork, among other configurations. After formation of thecommunication networks, satellite devices can selectively exchange (204)communications among the first orbital layer and the second orbitallayer.

To form the communication networks, various arrangements and assignmentscan be identified for associated satellite devices. Satellite cluster101 can form (203) the communication networks among the satellitedevices to selectively exchange communications among the first orbitallayer and the second orbital layer based at least in part on anoperational status of the communication network. The variouscommunication networks can be formed according to clustering definitions171 delivered by ground control system 170. The clustering definitionsindicate membership assignments for the first subset of satellitedevices and the second subset of satellite devices, and the clusteringdefinitions can further indicate a configuration establishing a forwardcommunication path and a reverse communication path within theassociated communication network.

Satellite cluster 101 establishes (205) a forward circulatingcommunication path in the orbital layers, and establishes (206) areverse circulating communication path in the orbital layers. In FIG. 1,upper layer 110 includes forward circulating network pathway 141 andreverse circulating network pathway 142, while lower layer 120 includesforward circulating pathway 143 and reverse circulating network pathway143. The forward communication paths formed in the orbital layerscirculate traffic of the communication networks with a “forwardhelicity” about an orbital direction of affected satellite device. Thereverse communication paths formed in the orbital layers circulatetraffic of the communication networks with a “reverse helicity” aboutthe orbital direction of affected satellite devices. Specifically, if anorbital direction of upper layer 110 is indicated by the arrow of orbit102, then a forward direction will align and propagate traffic througheach satellite device in the same direction of travel within the orbit,and a reverse direction will align and propagate traffic through eachsatellite device in the opposite direction of travel within the orbit,with the directions of travel approximated as a relatively straightline.

In this manner traffic-circulating two pathways are formed in eachlayer, with traffic passing through each satellite of the associatedcommunication network. For pathway 141, satellite forward routing ordercomprises 114-113-112-111, while for pathway 142 satellite reverserouting order comprises 111-112-113-114. Similar operation for pathways143-144 are described in FIG. 1. Failures about satellite devices mightthen cause an interruption in the pathways among satellites. However,since traffic can circulate in either direction, then redundant pathwaysare formed to ensure reliable communications among the satellite devicesof the layer. Although two layers are shown in FIG. 1 with separateforward/reverse pathways for each layer, it should be understood thatindividual satellite devices of both layers can share forward/reversepathways. Furthermore, layer-to-layer link 145 can be employed tocommunicate traffic among the individual layers.

Each satellite device determines (207) a traffic direction over which toroute traffic based on operational status of the communication paths.This operational status can be local status, such as status ofcommunication links formed among a current satellite device and one ormore peer satellite devices. This operational status can also bedetermined for the network as a whole, and reported among the satellitedevices. During routing of traffic of the communication network, ones ofthe satellite devices are configured to determine a traffic directionamong the forward communication path and the reverse communication pathover which to route the traffic based in part on the operational statusof the forward communication path and the reverse communication path.When the operational status of the communication network indicates theforward communication path of the communication network is experiencinga failure, ones of the satellite devices are configured to route thenetwork traffic for delivery to target satellite devices using thereverse communication path.

Once the layers are established, various enhanced operations can beprovided by the satellite cluster. For example, satellite-to-groundcommunications can be facilitated over the communication networks. Asource satellite device can identify network traffic for delivery toground control system 170, and transfer the network traffic for deliveryto ground control system 170 over the communication network. Thetransfer can occur over a particular layer, such as a layer of which thesource satellite device is a member. The transfer can also occur in aparticular pathway/direction over that layer, such as in a forward orreverse direction based in part on operational status of thecommunication network of that layer. Moreover, the source satellitedevice can transfer the network traffic to a peer satellite which cansubsequently transfer to another peer satellite, and so on, until a peersatellite is found that can route the network traffic to ground controlsystem 170. For example, the network traffic can originate at satellitedevice 113, and be routed in a selected forward or reverse direction ofpathways 141-142 until the network traffic reaches satellite device 111which currently has a communication link 151 established with groundcontrol system 170. Based at least on the operational status of thecommunication network indicates satellite device 111 can presentlycommunicate with ground control system 170.

In further examples, a satellite that can communicate with groundcontrol system 170 might not be included on a current orbital layer, andthus the network traffic can be routed to a different orbital layer,such as orbital layer 120 over link 145. Once the network traffic is onlayer 120, then satellite devices 121-124 can route the network trafficuntil a target satellite device is reached that can route the networktraffic to ground control system 170, such as indicated for satellitedevice 121 and link 152 in FIG. 1.

Turning back to the elements of FIG. 1, satellite devices 111-116 and121-126 can comprise various hardware and software elements included inan orbital package. In some examples, the satellite devices compriseCubeSat form-factor devices, although variations are possible. Satellitedevices can include one or more sensors, communication circuity,processing circuitry, and control/logistical management elements. Figurediscussions of satellite devices are included in FIG. 2 and FIG. 13below.

Satellites 111-116 and 121-126 each include a hardware and softwareconfiguration that permits applications to execute as virtual nodes onthe satellites. In some implementations, satellites 111-116 and 121-126may be launched using a launch system without applications, and insteadmay be provided with a base operating system, virtual machine images, orhypervisor that can be used to load and execute applications as providedin an uplink from ground control system 170. In other implementations,satellites 111-116 and 121-126 may be configured with a first set ofapplications capable of being executed via an operating system orhypervisor on the satellites. Thus, once into orbit, the applicationsmay initiate execution to provide the operations of the applications.These applications may further be added to, removed, and modified basedon information provided in the uplink from ground control system 170.

Ground control system 170 comprises one or more control systems,servers, distributed computing and storage systems, among otherelements. Typically, ground control system 170 includes one or morecommunication systems for receiving communications from satellitedevices and for transferring communications to satellite devices. Groundcontrol system 170 can include further network links to other networks,such as packet networks, the Internet, and other entities. In someexamples, software payloads are staged in ground control system 170 anddeployed to one or more satellite devices over ground-to-satellite links151-152. Once received by at least a first satellite device, thesesoftware payloads can be distributed over peer-to-peer communicationlinks and networks among the various satellite devices. Ground controlsystem 170 can receive network traffic from satellite devices and routethe network traffic to other network systems using include routes,bridges, switches, and other network handling equipment. Ground controlsystem 170 also can receive network traffic for delivery to thesatellite devices and transfer this network traffic for delivery to thesatellite devices for distribution of the network traffic over thevarious orbital layers, pathways, and peers of the satellite cluster.

Links 141-145 and links 151-152 each comprise one or more communicationpathways for exchanging network communications. Links 141-145 and links151-152 can each comprise various logical, physical, or applicationprogramming interfaces. Example links can use optical, air, space, orsome other element as the transport media. Links 141-145 and links151-152 can each use various protocols and formats, such as InternetProtocol (IP), Ethernet, transmission control protocol (TCP), WiFi,Bluetooth, other wireless data interfaces, or some other communicationformat, including combinations, improvements, or variations thereof.Links 141-145 and links 151-152 can each include direct links or mayinclude intermediate networks, systems, or devices, and can include alogical network link transported over multiple physical links. Links141-145 and links 151-152 can each include routers, switches, bridges,traffic handling nodes, and the like for transporting traffic amongendpoints.

FIG. 3 illustrates an expanded view 300 of an exemplary satellite device111 capable of providing a platform for virtual nodes according to animplementation. Any of satellites 111-116 and 121-126 can includesimilar features, and satellite device 111 is included as representativeof any satellite device. Satellite device 111 includes virtualizedexecution segment 301, control segment 302, and interface segment 303,which may be coupled using various communication links. Virtualizedexecution segment 301 is representative of a virtualized executionsystem, which includes a virtualized user space 340 for virtual nodes341-344, an operating system or hypervisor 335, a storage system 332 tostore the operating system and virtual user space, and a processingsystem 330. Control segment 302 further includes flight control system311 and propulsion navigation 310. Interface segment 303 furtherincludes user sensor system 320 and communication interface 321, whereincommunication interface 321 may be used for ground (gnd) communicationand inter-satellite (peer) communication.

Sensor system 320 may include one or more sensor devices, includingimaging sensors, temperature sensors, light sensors, signal qualitysensors, or some other similar sensor capable of interaction withvirtual nodes 341-344. In FIG. 3, sensors ‘A’ and ‘B’ are shown asillustrative of downward-facing sensors. It should be understood thatother sensors can be included, such as star sensors, space imagingsensors, radiation detectors, or other sensors.

As described herein, organizations may generate applications that arecapable of being deployed as virtual nodes on one or more satellites ofa satellite platform. These applications may be provided from a groundcontrol system, or may be provided from another satellite viacommunication interface 321 on satellite device 111. Once theapplications are provided, operating system/hypervisor 335, which isstored on storage system 332 and executed by processing system 330 mayprovide a platform for the execution of the applications. Here, eachapplication provided to satellite device 111 is executed as a separatevirtual node in virtual nodes 341-344, wherein the virtual nodes maycomprise full operating system virtual machines or containers capable ofsharing resources from the underlying operating system in storage system332.

To manage the execution of the virtual nodes, operatingsystem/hypervisor 335 may manage a schedule that is used to allocateprocessing resources of processing system 330 to each of the nodes, usersensors 320 to each of the nodes, and other similar resources onsatellite device 111. In particular, the schedule may be used to ensurethat each application is scheduled to receive processing resources fromprocessing system 330 during defined time periods, and receive access touser sensors 320 during defined time periods. In some implementations,one or more of the applications may execute during the same time periodon satellite device 111. These applications may use different sensors inuser sensors 320, may time share the use of sensors in user sensors 320,or may use the same data from user sensors 320 in their operation. Toallocate the sensors operating system 335 may be responsible forproviding each operating virtual node with a communication link to therequired user sensor, and deallocating or removing the communicationlink to the required sensor based on the scheduling. For example, animaging device may be accessed by virtual node 341 during a first timeperiod, wherein virtual node 341 may access the sensor based onaddressing information provided by operating system 335. Once the timeperiod expires, operating system 335 may prevent virtual node 341 fromaccessing the sensor, in some examples, by removing the addressingaccess of the virtual node, and allocating access of the sensor to asecond virtual node.

In addition to the virtual node operations provided in virtualizedexecution segment 301, satellite device 111 further includes controlsegment 302. Control segment 302, which may be communicatively linked tovirtualized execution segment 301 and interface segment 303, isresponsible for logistical control elements of the satellite device 111.These operations may include managing the deployment of solar panels onthe satellite, managing the positioning of the satellite with regards tothe Earth or the sun, or any other similar operation. In at least oneexample, flight control system 311 may monitor for requests fromoperating system 335, and determine whether the satellite is capable ofaccommodating the request from operating system 335. For example,virtual node 341 may generate a request to move a user sensor, whichalso requires movement using propulsion and navigation 310. In responseto the request, flight control system 311 may determine that themovement cannot be made, and may prevent the movement of the satelliteusing propulsion and navigation 310. Further, in some implementations,flight control system 311, may provide a notification to operatingsystem 335 and virtual node 341 indicating that the movement is notpermitted.

Although illustrated as a separate system in the example of FIG. 3, itshould be understood that in some examples, flight control system may beimplemented and stored on processing system 330 and storage system 332.However, it should also be understood that flight control system may bestored on a separate storage system and use a different processingsystem than operating system 335 and its corresponding virtual nodes.

Turning now to further configurations and operations of satelliteclusters and satellite platforms, FIGS. 4-6 are presented. FIGS. 4-6illustrates establishing pseudo-geosynchronous (or quasi-geosynchronous)windows formed by non-geosynchronous satellite devices. Typically, toachieve geosynchronous monitoring or positioning of a satellite over aplanet, such as Earth 440, a geosynchronous orbit (GEO) must beachieved. This geosynchronous orbit is at a much greater distance thanlow-earth orbiting (LEO) satellites, and has an accompanying difficultyin deployment. Communication latency and throughput also suffer withcommunications to satellites in geosynchronous orbit. In FIGS. 4-6, apseudo-geosynchronous operation is achieved using a cluster ofsatellites in low-earth orbit.

In FIG. 4, a pseudo-geosynchronous window 402 is established to achievemonitoring of a particular zone of interest by a satellite cluster. Thezone of interest can be tied to a particular geographic or atmosphericlocation, point, region, or area, and can be defined in any number ofways, such as geographic coordinates, using one or more globalpositioning systems (GPS, GLONASS, Galileo), latitude-longitudedefinitions, or other definitions. The zone of interest can also bedefined according to an object of interest that is detected or monitoredby the satellite cluster, and the object of interest can experiencemovement over time. For example, the zone of interest can correspond toa vehicle, animal, person, cloud formation, aircraft, or other motiveobject, and the zone of interest can be established to track the motiveobject. The zone of interest can also be defined according to signalstrength or communication link properties with ground system 430. Forexample, a satellite-to-ground link can be established between satellitecluster 401 and a ground communication system using continually shiftingsatellite devices in LEO. Thus, both static and dynamic zones ofinterest can be established, and pseudo-geosynchronous operationachieved by members of a satellite cluster in LEO.

FIG. 4 includes satellite environment 400 comprising satellite cluster401 that includes satellite devices 410-414. FIG. 4 also includes groundsystem 430, Earth 440, and zone of interest 441. In operation, membersof satellite cluster 401 can communicate over one or more communicationlinks, such as those described for layer communications in FIG. 1,although variations are possible. Satellites 410-414 each move in anorbit about Earth 440, and this orbit is illustrated in FIG. 4 using theindicated orbital direction. It should be understood that differentorbits and orbital directions can be employed.

As the example in FIG. 4 includes a sensory-based zone of interest 441,a current satellite device is configured to perform sensorymeasurements, such as a visual, infrared, or ultraviolet imaging, RFimaging or detection, or other sensor-based measurements for the zone ofinterest. Sensing line-of-sight 423 is indicated in FIG. 4 between acurrent satellite device and the zone of interest.

To establish the zone of interest, ground system 430 can transfer one ormore task instructions to satellite cluster 401 over ground-to-satellitelink 424. As with the peer-to-peer communication examples herein, anysatellite device can receive the task instructions and distribute thetask instructions to other peer satellites, such as peer satellites of aparticular orbital layer. As each satellite enters thepseudo-geosynchronous window, state information indicates the taskinstructions as well as any persistent state transfer from the satellitedevices that leave the pseudo-geosynchronous window. The stateinformation can include imaging data, sensor data, processed imaging orsensor data, or other information, such as tracking information, objectrecognition information, object trajectory information, and otherintelligence related to the zone of interest. When the state informationcomprises sensor data captured by others of the satellite devices duringpassage through the pseudo-geosynchronous window, further satellitedevices passing through the pseudo-geosynchronous window can thencapture further sensor data for incorporation into the stateinformation.

Thus, a continual ‘chain’ of monitoring is achieved for zone of interest441 using pseudo-geosynchronous window 402. As each satellite deviceenters pseudo-geosynchronous window 402, the satellite device isconfigured to begin a monitoring operation indicated by the taskinstructions or indicated by state information transferred from one ormore satellite devices exiting pseudo-geosynchronous window 402. Duringtransit through pseudo-geosynchronous window 402, the associatedsatellite devices perform one or more tasks indicated by the taskinstructions or state information, such as monitoring underlyingobjects, regions, or zones. Responsive to exiting pseudo-geosynchronouswindow 402, the satellite devices can then transfer state information ortask instructions to a further, subsequent, satellite device that isentering pseudo-geosynchronous window 402. Thus, another ‘entering’ or‘incoming’ satellite device resumes the task that is ended by the‘exiting’ or ‘outgoing’ satellite device. The pseudo-geosynchronouswindow can be established as synchronous to a surface of Earth 440 (orto a motive object thereof) without the actual satellite devices beingin a geosynchronous orbit.

The state information or the task instructions can comprise one or morevirtual machine images or virtual machine state information. Eachsatellite device entering the pseudo-geosynchronous window can execute aparticular virtual node to perform one or more corresponding tasks. Thestate information can be used to provision the virtual node, such as toresume a task of a satellite leaving the pseudo-geosynchronous window.In some examples, the state information comprises processed image datafor tracking, identifying, and reporting various objects of interest. Aseach satellite circulates through the pseudo-geosynchronous window, thestate information can be sequentially transferred by exiting satellitedevices (421) and updated into entering satellite devices (422) tocontinually monitor zones of interest. These tasks and state informationcan be achieved using one or more virtual nodes executed by thesatellite devices, so that when exiting the pseudo-geosynchronouswindow, the associated virtual node of a satellite device can transferan updated state or data to another satellite device which initiates afurther virtual node for continuation of the task with respect to apseudo-geosynchronous window.

Turning now to FIG. 5, a pseudo-geosynchronous window 502 is establishedfor exchanging communications of satellite cluster 501 with groundsystem 430. A zone of interest 541 can be tied to a particulargeographic point, region or area, and can be defined in any number ofways, such as geographic coordinates, using one or more globalpositioning systems (GPS, GLONASS, Galileo), latitude-longitudedefinitions, or other definitions. The zone of interest can also bedefined according to signal strength or communication link propertieswith ground system 430. For example, a satellite-to-ground link 423 canbe established between satellite cluster 401 and a ground communicationsystem using continually shifting satellite devices in LEO. Thus, bothstatic and dynamic zones of interest can be established, andpseudo-geosynchronous operation achieved by members of a satellitecluster in LEO.

FIG. 5 includes satellite environment 500 comprising satellite cluster501 that includes satellite devices 410-414. FIG. 5 also includes groundsystem 430, Earth 440, and zone of interest 541. In operation, membersof satellite cluster 501 can communicate over one or more communicationlinks, such as those described for layer communications in FIG. 1,although variations are possible. Satellite devices 410-414 each move inan orbit about Earth 440, and this orbit is illustrated in FIG. 4 usingthe indicated orbital direction. It should be understood that differentorbits and orbital directions can be employed. FIG. 5 also includessatellite devices 515 which might be in a different orbit than satellitedevices 410-414, such as a different layer as found in FIG. 1. Aninter-orbit or inter-layer communication link 141 can be established forcommunication with satellite devices 515.

As the example in FIG. 5 includes a communication link-based zone ofinterest 541, a current satellite device is configured to perform signalstrength measurements, RF signal strength or optical signal strengthdeterminations for establishment of pseudo-geosynchronous window 502.Communications line-of-sight link 523 is indicated in FIG. 5 between acurrent satellite device and the zone of interest. Although a signalstrength can be used to establish the pseudo-geosynchronous window,other considerations such as a geographic locations or coordinates ofground system 430 can also be employed to defined thepseudo-geosynchronous window.

To establish the zone of interest, ground system 430 can transfer one ormore task instructions to satellite cluster 501 over ground-to-satellitelink 523. As with the peer-to-peer communication examples herein, anysatellite device can receive the task instructions and distribute thetask instructions to other peer satellites, such as peer satellites of aparticular orbital layer or to satellite devices 515 of another orbitallayer. As each satellite enters the pseudo-geosynchronous window, stateinformation indicates the task instructions as well as any persistentstate transfer from the satellite devices that leave thepseudo-geosynchronous window. The state information can includeoriginated data, processed data, network traffic, data packets, networkcommunications, or other information.

Thus, a continual ‘chain’ of monitoring is achieved for zone of interest541 using pseudo-geosynchronous window 502. As each satellite deviceenters pseudo-geosynchronous window 502, the satellite device isconfigured to begin a communication routing operation indicated by thetask instructions or indicated by state information transferred from oneor more satellite devices exiting pseudo-geosynchronous window 502.During transit through pseudo-geosynchronous window 502, the associatedsatellite devices perform one or more tasks indicated by the taskinstructions or state information, such as routing traffic to groundsystem 430 over link 523, receiving communications from ground system430 for routing to satellite devices of cluster 501, or other trafficrouting operations. Responsive to exiting pseudo-geosynchronous window502, the satellite devices can then transfer state informationcomprising routing instructions, or other task instructions to afurther, subsequent, satellite device that is enteringpseudo-geosynchronous window 502. Thus, another ‘entering’ or ‘incoming’satellite device resumes the task that is ended by the ‘exiting’ or‘outgoing’ satellite device. The pseudo-geosynchronous window can beestablished as synchronous to a surface of Earth 440 without the actualsatellite devices being in a geosynchronous orbit.

The state information or the task instructions can comprise one or morevirtual machine images or virtual machine state information, or routinginstructions for a routing or traffic handling virtual node. Eachsatellite device entering the pseudo-geosynchronous window can execute aparticular virtual node to perform one or more correspondingrouting/communication tasks. The state information can be used toprovision the virtual node, such as to resume a task of a satelliteleaving the pseudo-geosynchronous window. As each satellite circulatesthrough the pseudo-geosynchronous window, the state information can besequentially transferred by exiting satellite devices (421) and updatedinto entering satellite devices (422) to continually communicate withground system 430 in zone of interest 541. These routing/communicationtasks and state information can be achieved using one or more virtualnodes executed by the satellite devices, so that when exiting thepseudo-geosynchronous window, the associated virtual node of a satellitedevice can transfer an updated state or routing instructions to anothersatellite device which initiates a further virtual node for continuationof the task with respect to a pseudo-geosynchronous window. Thus, duringthe orbital passage within quasi-geosynchronous window 502, each passingsatellite device is configured to direct an associated communicationsystem of the passing satellite device to route communications trafficreceived from other satellite devices in accordance with network routinginstructions for exchange of at least a portion of the communicationstraffic of satellite cluster 502 with a fixed location groundcommunication system.

FIG. 6 includes further example operations for the elements of FIGS. 4and 5. In FIG. 6, a satellite cluster establishes (601) apseudo-geosynchronous window corresponding to an underlying zone ofinterest. The underlying zone of interest can be defined geographiccoordinates, proximity to underlying geographic features, based ontracked objects, based on signal properties of communication link with aground station, or other definitions. Orbital or spatial positioning ofthe satellite devices with relation to the zone of interest can be usedto define the pseudo-geosynchronous window within the orbit of thecluster of satellites. The plurality of satellite devices of thesatellite cluster are configured to determine entry into or exit fromthe pseudo-geosynchronous window based at least determining overheadproximity to the underlying zone of interest. Entry into and exit fromthe pseudo-geosynchronous window can be determined by the plurality ofsatellite devices based at least on determining the overhead proximityin relation to an object of interest that corresponds to the underlyingzone of interest, based on signal strength of communications with aground system corresponding to the underlying zone of interest, or basedon other entry and exit criteria, including combinations thereof.

Each satellite device exiting from the pseudo-geosynchronous windowtransfers (602) state information to entering satellite devices. Theentering satellite devices each detect (603) orbital passage within thepseudo-geosynchronous window, and responsively execute (604) adesignated software payload in accordance with the state information.The state information can be related to execution of a designatedsoftware payload from outgoing satellite devices leaving thepseudo-geosynchronous window for receipt by target satellite devicesentering the pseudo-geosynchronous window. In some examples, receipt ofthe state information by a target satellite device can trigger executionof a virtual node related to the state information. During orbitalpassage within the pseudo-geosynchronous window, the target satellitedevices are configured to execute a designated software payload inaccordance with the state information, which might include executing oneor more applications as virtual nodes in a virtualized execution systemof the satellite device. Responsive to detecting exit from thepseudo-geosynchronous window, outgoing satellite devices configured todetermine at least a portion of the state information, and deliver atleast the portion of the state information to one or more new targetsatellite devices. As an alternative to transfer of the stateinformation upon exit by the exiting or outgoing satellite devices, theinbound or entering satellite devices can request the state informationresponsive to detecting entry into the pseudo-geosynchronous window.

In some examples, the state information comprises routing instructions,and during the orbital passage within the pseudo-geosynchronous window,target satellite devices are configured to route communications trafficreceived from others of the satellite devices for delivery to the groundsystem using the routing instructions. The others of the satellitedevices are configured to route the communications traffic for deliveryto the target satellite devices through zero or more peer satellitedevices, depending on how many ‘hops’ might be necessary to reach thetarget satellite devices in the pseudo-geosynchronous window. When asubset of the satellite devices orbit in a higher orbital distance fromones of the satellite devices that pass through thepseudo-geosynchronous window, then the subset of the satellite devicescan be configured to route communications of the subset for delivery toa ground system via the ones of the satellite devices that pass throughthe pseudo-geosynchronous window, such as using layer-to-layercommunication links.

Turning now to FIGS. 7-9, various examples are presented for configuringclusters of satellites to support specialized roles among members of anorbital satellite cluster or orbital satellite platform. Each of themembers can be assigned to handle one or more specialized tasksaccording to a skill set or provisioning configuration of the satellitedevices. Peer-to-peer communications are employed to transfer workloadsor data among the cluster of satellite devices to reach the varioussatellite devices configured to perform the specialized tasks. Thesespecialized tasks include data processing tasks, graphics processingtasks, communication tasks, data storage tasks, peer monitoring tasks,sensing tasks, or others, including combinations thereof.

FIG. 7 is a first example that employs specialized tasks in satelliteenvironment 700. Satellite environment 700 includes satellite cluster701 that comprises a plurality of satellite devices 710-714. Eachsatellite device is in orbit around Earth 740, and the satellite devicesmight be included in one or more orbital layers. Ground system 730 canbe employed to communicate from one or more ground systems to satellitecluster 701 over link 742.

Communication links 721-724 are established among associated ones of thesatellite devices, and each of the satellite devices can act as ‘peers’for one another. Communication links 721-724 can form a communicationnetwork comprising one or more pathways that might include forward andreverse circulation directions, depending upon the network topologyemployed. Communication links 721-724 might comprise wireless linkswhich can include one or more RF links or optical links that carrynetwork traffic employing one or more networks or communicationprotocols. The network traffic can include packetized communications,such as IP communications, among others, including customizedcommunication formats.

Each of satellite devices 710-714 can have one or more designated roleswhich are specialized to a particular task or tasks. These roles caninclude those mentioned above, as well as a data processing role, a datastorage role, an imaging role, a satellite-to-ground communication role,and a virtualized software execution role. The specialized roles can bebased on provisioning properties or versioning properties among hardwareelements and software elements of each of the satellite devices.

For example, a first satellite device might include a graphicsprocessing unit (GPU) that can handle a higher level of graphics dataprocessing, while a second satellite device might lack a GPU but includea specialized software package for processing image data to performobject tracking or object recognition. Imaging data might be passed froma source satellite device 710 that captures line-of-sight imaging data741 to another satellite device with a GPU 712 that can process theimaging data to apply one or more digital filters or otherpre-processing steps, and then yet another satellite device can receivethe pre-processed imaging data to perform object recognition processeson that data. A final satellite device 714 might have a communicationrole for satellite-to-ground communications based on appropriatecommunication circuitry, antenna arrangements, or proximity to groundstation 730. This final satellite can receive the processed imaging dataafter the GPU processing or object recognition process has beencompleted, and transfer for delivery to ground station 730 for furtherrouting to other network nodes, servers, storage systems, distributedcomputing platforms—possibly over one or more packet networks toterrestrial destinations. Instead of transferring to ground station 730,a storage-specific satellite device 711 might be employed to store theimaging data or processed imaging data for later transfer to othersystems or for later comparison with other imaging data for objecttracking, time-lapsing, video capture, or related processes. In furtherexamples, the storage role satellite device 711 might be employed tostore virtual machine images, software payloads, applications, orvirtual machine execution state information for provisioning to othersatellite devices.

The satellite devices of satellite cluster 701 can be configured toidentify one or more target satellite devices among satellite devices ofsatellite cluster 701 to handle specialized tasks based in part on anattribute scoring metric determined for the satellite devices. Theattribute scoring metric can indicate competency ratings for each of thetarget satellite devices for at least a portion of the specializedroles. As one example, specialized role schedule data structure 750 isshown in FIG. 7 for exemplary satellite device 713, and each satellitedevice can include similar data structures. This data structure canindicate identifiers or identities of each of the satellite devices insatellite cluster 701 in a first column, and then in a second andfurther columns indicate competency scores for a variety of specializedroles, such as those mentioned herein. When a satellite device desiredto employ a specialized role, then that satellite device can consultschedule 750 to select which satellite devices are best suited for thespecialized data or communication task. Data, communications, stateinformation, or task instructions can then be transferred for deliveryto the selected satellite device or devices. This transfer can occurover one or more peer-to-peer satellite likes, such as links 721-724 inFIG. 7. In further examples, a data structure like schedule 750 mightnot be employed to identify or select specific satellite devices.Instead, a satellite device might transfer the data, communications,state information, or task instructions for delivery to any satellitedevice in a broadcast manner, and a satellite device that matches aspecified role indicated in the task instructions can responsively takeaction based on receiving the data, communications, state information,or task instructions, while other satellite devices might ignore thetransfer.

FIG. 8 is a further example of role specialization among satellitedevices of a satellite cluster. Satellite configuration 800 includes aplurality of satellite devices 811-816, each communicatively coupled byone or more communication links 821-825. In operation, one or more amongsatellite devices 811-816 can have specialized roles assigned ordesignated. These roles can be established based on software or hardwareelements included in each of satellite devices 811-816.

When software elements define the specialized roles, the roles can beestablished based on which virtual machine images are currently residenton each satellite device, software revisions currently updated on eachsatellite device, or properties other software elements currentlypresent on each satellite device 811-816. When hardware elements definethe specialized roles, the roles can be established based on hardwareelements, circuitry, processing elements, communication elements,transmitter or receiver properties, antenna configurations, antennaalignments or properties, data storage devices or capacities, dataprocessing capabilities, data processing speeds, data processingavailability or utilization levels, communication bandwidth,communication frequencies, communication signal strengths, sensor types,sensor capabilities, sensor availability, sensor alignment, satellitepositioning, or other properties related to presence of hardwareelements or current functionality of hardware elements.

Example satellite device components are shown for satellite device 813,and these can be included in any of satellite devices 811-816. Satellitedevice 813 includes one or more virtual nodes executed by a virtualizedexecution system of satellite device 813 provided by operating system(OS)/hypervisor 832 and various processing system and memory deviceelements not shown for clarity. Furthermore, a communication system 831is included for peer-to-peer communication among satellite devices, orfor satellite-to-ground communications in some examples. A virtual nodecan be configured as a task execution system to handle the specializedtask handling, which might include elements such as a task discriminatorand task executor. The task discriminator can determine if an inboundtask is mean for the particular satellite devices that receives thetask, as well as determine which satellite devices of the cluster havespecialized roles, perform scoring or ranking of the competencies amongsatellite devices with respect to the specialized roles, among otherfeatures. The task executor can handle local execution of thespecialized tasks when directed to the particular satellite device. Thislocal execution might include spawning or initiating one or moreadditional virtual nodes to perform the task, monitoring the taskperformance and completion, and transferring data or state informationfor delivery to another task or satellite device upon completion. Whenconfigured as a satellite-to-ground routing specialized role, taskexecutor might operate as a network traffic router or bridge forexchanging network traffic with a ground system, with satellite devicesof another orbital layer, or other communication endpoints.

Each of the satellite devices of FIG. 8 can include a communicationsystem configured to receive task descriptions from at least one peersatellite device, and a task execution system configured to identifyspecialized roles indicated by the task descriptions and determine ifthe satellite device supports the specialized roles based at least on acurrent provisioning of software elements and hardware elements. Basedat least on the satellite device supporting one or more of thespecialized roles, the task execution system is configured to executeone or more tasks in accordance with associated task descriptions. Basedat least on the satellite device not supporting the one or more of thespecialized roles, the task execution system configured to instruct thecommunication system to transfer the associated task descriptions fordelivery to a further peer satellite device. As mentioned above, thetask instructions or task data might comprise state information relatedto execution of virtual nodes by the task execution system of asatellite device. In these examples, based at least on a satellitedevice supporting the one or more of the specialized roles, theassociated task execution system can be configured to execute one ormore software applications as associated virtual nodes according to thestate information.

In a specific example, origin satellite 811 can originate data forprocessing by another satellite device with a role specialized to thetype of data processing desired for the data originated by satellite811. Satellite 811 can transfer this task data 850, along with anyassociated task instructions, for delivery to the specialized satellitedevice—namely satellite device 813. Satellite device 813 can receivetask data 850, determine that the task data is meant for processing bysatellite device 813, and being a data processing task commensurate withany task instructions that accompany task data 851. The task data mightinclude imaging data for which additional graphics processing is desiredby satellite device 811, and thus satellite device 813 can perform thisadditional graphics processing. Other examples of specialized roles canbe employed, such as communication routing, data storage, softwareprovisioning, virtual machine image or state distribution, among others.

Once satellite device 813 has completed the associated data processingon task data 850, the task instructions might indicate that theprocessed data is to be returned to satellite device 811. However, inthis example, the task instructions indicate that the processed data isto be transferred for delivery to a ground system. Satellite device 813can identify a satellite device of the cluster which has a specializedrole of ground communications, and transfer the processed data asfurther task data 851 for delivery to that satellite device—namelysatellite device 816. It should be noted that task data 850 and taskdata 851 can pass through one or more peer satellite devices en route tothe destination satellite devices. These peer satellite devices can bemembers of a communication network, such as those described in FIG. 1for forward/reverse circulating network configurations. Since the peersatellite devices are either not identified as a destination in the taskinstructions, or lack the specialized roles, these peer devices continueto transfer the task data to further peer devices. The task instructionsmight include one or more network packets with addressing information orheader information that indicates a particular satellite device or taskrole desired for the accompanying task data. The task data might beincluded in payload portions of the network packets. Responsive toreceiving further task data 851, satellite device 816 can determine thattask data 851 (or as indicated by accompanying task instructions) is tobe routed to a ground system by satellite device 816. Satellite device816 can then route task data 852 for delivery to the ground system andfurther distribution of the processed data to terrestrial computingsystems.

FIG. 9 is a further example of operation for specialized roles inclustered satellite devices of FIG. 8. In FIG. 9, cluster 800 defines(901) specialized roles among satellite devices based on includedelements targeted to the specialized roles. Each of the satellitedevices identifies (902) data tasks to be serviced using one or more ofthe specialized roles, and determines (903) target satellite devices tohandle the data tasks based on attributes indicating the specializedroles among the target satellite devices. The selection of targetsatellite devices can be made based in part on an attribute scoringmetric determined for the target satellite devices, where the attributescoring metric indicates competency ratings for each of the targetsatellite devices for at least a portion of the specialized roles. Thesatellite devices then transfer (904) task data, along with anyassociated task instructions, for delivery to the target satellitedevices for performing the data tasks.

In some examples, the task data or task instructions comprise stateinformation related to execution of virtual nodes by the satellitedevices, and the target satellite devices include virtualized executionsystems configured to receive the state information and execute one ormore software applications as virtual nodes according to the stateinformation. Furthermore, individual ones of the satellite devices canbe further configured to transfer the task data and task instructionsthrough one or more peer satellite devices of the satellite cluster toreach the target satellite devices. Responsive to receiving the taskdata, each associated peer satellite device can be configured toevaluate a received task data against one or more attributes of theassociated peer satellite device to determine if the associated peersatellite device should act in accordance with the task data or transferthe task data to at least one further peer satellite.

Turning now to FIGS. 10-12, these Figures detail various examples ofstate transfer among satellite devices of an orbital satellite clusteror orbital satellite platform. The state transfer can be facilitatedusing a storage-area-network (SAN) based configuration, where at leastone satellite device of the satellite cluster can include one or moredata storage systems for storing state information related to executionof virtual nodes by other satellite devices. However, in satellitesystems, bandwidth of inter-satellite communications might be limited orunreliable. Moreover, communication with ground systems can beintermittent and low-bandwidth. Thus, the various examples in FIGS.10-12 include enhanced operations for handling state transfer amongsatellite devices in a satellite cluster, where bandwidth-limitedoperations might be encountered.

In ground-based virtualized execution systems, virtual machines orvirtual nodes might be ‘booted’ from a remote source, such as from adistant server over a high-speed network link. These high-speed linksmight include gigabit Ethernet or faster configurations which allow forhigh-bandwidth and real-time transfer of virtual machine images orvirtualized containers as-needed for booting virtual machines or virtualnodes. However, in space-based systems, such as satellite clusters orplatforms, links are typically wireless (RF or optical) and aretypically less reliable, lower bandwidth, and may be intermittentdepending on ambient radiation conditions, satellite orientation,distance, passage over signal horizons, line-of-sight challenges, or dueto other considerations. Moreover, transfer of virtual machine orvirtual node information from ground systems might not always beachievable due to lack of line-of-sight with an associated ground systemby many of the satellite devices of the cluster. Motion of thesatellites themselves can also complicate these transfers. Thus, it canbe difficult to provision virtual machine images and other virtual nodestate information among orbiting satellites.

FIG. 10 is a first example configuration for state transfer amongsatellite devices. In FIG. 10, system 1000 is presented that includes aplurality of satellite devices, such as satellite devices 1010-1013.These satellite devices can be deployed into one or more orbitalconfigurations, such as a layered configuration illustrated in FIG. 1. Acirculating network can be formed among the satellite devices, or apoint-to-point communication scheme might instead be employed. However,for the purposes of the example in FIG. 10, satellite device 1011 doesnot have a direct communication path to satellite device 1012, and mustcommunicate through one or more peer satellite devices. Communicationlinks 1021-1024 forms a peer-to-peer communication network, and eachlink can comprise any of the wireless communication links discussedherein.

In operation, satellite device 1010 is configured to perform one or moretasks, such as by executing one or more applications using virtual nodesin a virtualized execution system. Periodically, satellite device 1010updates current state of the virtual nodes with satellite 1012 that actsas a part of a storage area network (SAN) for the satellite cluster.Satellite 1012 can receive the periodic state updates and stores thestate updates using storage system 1080 comprising one or morenon-transitory computer-readable media, such as solid state media, flashmemory, magnetic media, phase change media, resistive memory, or otherstorage media. In FIG. 10, state updates 1081 can be storedincrementally, or in a replacement manner.

Satellite device 1011 is configured as a backup satellite device forsatellite device 1010 in case or error, malfunction, or failure ofsatellite device 1010. This backup by satellite 1011 can includeresuming one or more tasks being performed by satellite device 1010after detection of an issue with satellite device 1010. However,satellite device 1011 can only resume the task being performed bysatellite device 1010 if current state information is able to betransferred to satellite device 1011 from either satellite 1010 orsatellite 1012 which stores the state updates.

In FIG. 10, an example operation is provided to handle this statetransfer. Initially, satellite device 1010 performs one or more tasksusing virtual nodes as discussed herein. State updates related to theexecution of the virtual nodes is updated to specialized storagesatellite device 1012 over link 1022. Satellite device 1011 monitors forfailures of satellite device 1010. This monitoring can instead beperformed by satellite device 1012 in other examples. In FIG. 10,satellite device 1012 becomes unreachable over links 1021 and 1022, andthus a failure is determined to be occurring. Responsive to thisdetected failure, satellite device 1011 can attempt to get current stateinformation for resuming a task of satellite device 1010. However, sincelinks 1021-1022 are no longer functioning, satellite device 1011receives this state information from satellite device 1012 over analternate route, namely links 1023-1024, and though peer satellitedevice 1013. In one example, further updated state information wasavailable in satellite device 1010 but never transferred for storage bysatellite device 1012, namely ‘state 4’ in FIG. 10. Thus, only thelatest ‘state 3’ is available for transfer to satellite device 1011.Once this ‘state 3’ is received, satellite device 1011 can initiate oneor more virtual nodes according to the state information and resume oneor more tasks of satellite device 1010.

FIG. 11 illustrates a further example of the elements of FIG. 10, namelyin system 1100 that also include satellite devices 1010-1013communicating over associated links 1021-1024. However, FIG. 11 addshigh-bandwidth link 1125 and designates links 1023-1024 as low-bandwidthlinks. The bandwidth of each of these links can vary in time due thepresent conditions and other factors mentioned herein. However, once abandwidth determination has been made for each of the links, apredetermined threshold bandwidth level can be used to determine a levelof “statefulness” to transfer to backup satellite devices which acts asa monitoring peer for satellite devices 1010.

The level of statefulness can correspond to level of detail ordescription indicated in a state information transfer. In one example, ablock-level state transfer can be provided, where a block-levelrepresentation of changes to a virtual node are described in the stateinformation. In another example, a file-level state transfer can beprovided, where a data file-by-file representation of changes to avirtual node is described in the state information. Typically, thefile-level statefulness requires less bandwidth to transfer to asatellite device, however this file-level statefulness may not provide alevel of detail needed to perfectly replicate a virtual node or virtualmachine execution state. A block-level statefulness, on the other hand,can comprise a more complete replication of the execution state of avirtual node or virtual machine, but requires more bandwidth to transferamong satellite devices.

In FIG. 11, an example operation is provided to handle this statetransfer. Initially, satellite device 1010 performs one or more tasksusing virtual nodes as discussed herein. State updates related to theexecution of the virtual nodes is updated to specialized storagesatellite device 1012 over link 1022. Satellite device 1011 monitors forfailures of satellite device 1010. This monitoring can instead beperformed by satellite device 1012 in other examples. In FIG. 11,satellite device 1012 becomes unreachable over links 1021 and 1022, andthus a failure is determined to be occurring. Responsive to thisdetected failure, satellite device 1011 can attempt to get current stateinformation for resuming a task of satellite device 1010. However, sincelinks 1021-1022 are no longer functioning, satellite device 1011receives this state information from satellite device 1012 over analternate route.

However, in FIG. 11, the alternative route can include either links1023-1024 though peer satellite device 1013, or a more direct route overlink 1125. In this example, link 1125 is considered high-bandwidth andcapable of transferring a block-level state 1183 stored by satellitedevice 1012, while links 1023-1024 are considered low-bandwidth and notcapable of transferring a block-level state 1183 to satellite device1011 from satellite device 1012 in a timely manner. Instead oftransferring the block level state 1183, satellite device 1012 mightelect to send the lower-intensity but less accurate file-level state1182 for delivery to satellite device. The various bandwidths,thresholds, and timeliness factors can vary and be based onpredetermined levels, predetermined time delays to resume operation of afailed satellite device, or other factors.

A storage platform based in satellite device 1012 (i.e. elements ofstorage system 1080) can be executed as one or more virtual nodes on avirtualized execution system of satellite device 1012 and configured toselect a level of statefulness for delivery of the state information topeer satellite device 1011 designated as an operational backup for theactive satellite device 1010. This level of statefulness can be selectedbased at least on a communication link quality between the satellitedevice and the peer satellite device. For example, based at least inpart on the communication link quality falling below a predeterminedthreshold, the storage platform can be configured to transfer file-levelstate information for delivery to the peer satellite device over links1024-1023 and peer satellite device 1013. Based at least in part on thecommunication link quality exceeding the predetermined threshold, thestorage platform can be configured to transfer block-level stateinformation for delivery to the peer satellite device overhigh-bandwidth link 1125.

Once satellite device 1011 receives the state information transferred bysatellite device 1012, satellite device 1011 can begin executing one ormore virtual nodes to resume tasks of satellite device 1010. However,the state information might be incomplete to fully define a virtual nodeor virtual machine, especially in the file-level state transfer inbandwidth-limited scenarios. Responsive to receiving file-level stateinformation, satellite device 1011 can be configured to resume theactivity of the active satellite device by at least performing adifferential update of a virtual machine image already resident onsatellite device 1011 using the file-level state information.

The differential update can differentially patch files or replace filesinside a virtual node or virtual machine so as to recreate a block-levelstate using only a portion of the data that would normally accompany ablock-level state transfer. However, a base level of provisioning shouldexist in satellite device 1011 before the file-level differentialpatching can occur. Thus, satellite device 1011 might be pre-provisionedwith a baseline virtual machine image, virtual node, container, or othervirtualized data entity that can be later patched in a differentialmanner to boot the virtualized data entity and resume operation ofsatellite device 1010 according to the latest state informationavailable.

Satellite device 1011 might be selected as a backup to satellite device1010 based in part on a current provisioning level or based on currentprovisioning attributes available to support execution of the virtualnode to be resumed. The provisioning attributes might comprise versionlevels of one or more virtual machine images resident on the peersatellite device, or might comprise specific applications needed toexecute one or more tasks according to the transferred stateinformation. Responsive to one or more of the satellite devices lackingthe provisioning attributes to support execution of the active virtualnode, at least one among active satellite device 1010 and storagesatellite device 1012 can be configured to update a software portion ofthe one or more of the satellite devices to include the provisioningattributes to support execution of the active virtual node. Once thesoftware portion is updated, such as to update a baseline virtualmachine image, application version, or other software element, then theassociated updates satellite device can be slated for backup satellitedevice to satellite device 1010. A differential update can be performedresponsive to failures of satellite device 1010.

Although the preceding discussion is related to backup operations for anactive satellite device, the operations for differential state transferbased on a current level of software provisioning can be applied to theother examples herein. For example, specialized roles among satellitescan be defined according to provisioning attributes of particular targetsatellite devices that are available to support execution of a virtualnode on those target satellite devices. State transfer during the tasktransfer processes can include a differential updating of the baselinevirtual machine already found on the target satellite devices. Thedifferential updating can be based on block-level or file-leveltransfers.

FIG. 12 includes further examples of state transfer operations 1200among satellite devices for updating baseline provisioning of softwareelements of satellite devices. In FIG. 12, an initial satellite device1210 is designated with a task/role capability, such as the specializedtasks or specialized roles presented herein. This satellite device mightwant to identify one or more peer satellites to act as backup satellitedevices in case of failure, malfunction, or errors of the initialsatellite device 1210. In FIG. 12, satellite devices 1211-1212 areinitially identified as candidate backup satellite devices.

Satellite device 1210 detects capabilities of these candidate satellitedevices 1211-1212, such as a level of software provisioning, attributesrelated to virtual node execution, software versions, operating systemversions, kernel versions or patch levels, or other softwareprovisioning capabilities. In FIG. 12, satellite device 1211 isdisqualified as lacking one or more provisioning capabilities, whilesatellite device 1212 is identified as satisfying the one moreprovisioning capabilities. Satellite device 1210 can then establish apeering/backup arrangement with satellite device 1212, where satellitedevice 1212 monitors for failures of satellite device 1210 and resumesoperation of one or more tasks of satellite device 1210 using variousstate information, such as described above.

However, background provisioning of satellite device 1211 might bedesirable, such as to have a further backup or to increase thecapabilities of satellite device 1211 to support future operations.Thus, either satellite device 1210 or another satellite device can begina background provisioning updated to satellite device 1211 to bringsatellite device 1211 into alignment with one or more provisioningcapabilities. In one example, a storage-centric satellite device 1213can be employed that stores baseline provisioning information in storagesystem 1214. Satellite device 1213 can update software elements ofsatellite device 1211. As shown in FIG. 12, these software elementsmight include virtual machine images, software, applications, stateinformation, or user data, among other data or software elements. Oncesatellite device 1211 has been provisioned to a sufficient level,satellite device 1211 might be designated as a backup satellite devicefor satellite 1210 to achieve further operational redundancy forsatellite device 1210.

These operations can be advantageous when a new application or task isuploaded to a satellite cluster from a ground station, and not allmembers of a satellite cluster have been provisioned with the softwareelements to support that application or task. In this manner, a softwareapplication or task can be deployed over time to members of a satellitecluster while satellite devices can begin these new operations onceachieving a provisioning level. Moreover, since satellite devices aretypically deployed in an orbital configuration, a software payload mightbe transitioned from one satellite device to another satellite device asneeded or last-minute to support a specialized task corresponding to azone of interest. This last-minute provisioning can ensure thatsatellite devices are provisioned with software elements prior toentering a pseudo-geosynchronous window so that a state transfer from anexiting satellite device can find appropriate software elements alreadyresident on the entering satellite devices to perform a designated taskwithin the pseudo-geosynchronous window.

Furthermore, when a layered orbital arrangement is employed, a first setof satellite devices might be in a lower orbital layer than a second setof satellite devices. At least one of the satellite devices orbiting inthe lower orbital layer might comprise a virtualized execution systemconfigured to maintain associated state information related to executionof virtual nodes. A communication network among the satellite devicescan be configured to transfer the associated state information over thecommunication network for delivery to at least one peer satellite deviceorbiting in the second orbital layer and configured as a backup to theat least one of the satellite devices. These enhanced provisioningtechniques can be applied to the layered arrangements, where only afirst orbital layer has a line-of-sight established with a groundcommunication system that initially provides software payloads fordeployment among the satellite cluster. Once a first layer has beenprovisioned with the software payloads, then a further layer can beprovisioned for deployment of the software payloads over that furtherlayer.

FIG. 13 illustrates a satellite computing system 1300 to provide avirtualized satellite application platform according to animplementation. Computing system 1300 is representative of any computingsystem or systems with which the various operational architectures,processes, scenarios, and sequences disclosed herein for a satellitedevice may be implemented. Computing system 1300 can be an example of asatellite device from any of the preceding Figures, although otherexamples may exist. Computing system 1300 comprises communicationinterface 1301, sensors 1302, and processing system 1303. Processingsystem 1303 is linked to communication interface 1301 and sensors 1302.Sensors 1302 may comprise imaging sensors, heat sensors, light sensors,or some other similar type of sensor. Processing system 1303 includesprocessing circuitry 1305 and memory device 1306 that stores operatingsoftware 1307. Computing system 1300 may include other well-knowncomponents such as a battery, solar panels, and enclosure that are notshown for clarity.

Communication interface 1301 comprises components that communicate overcommunication links, such as network cards, ports, radio frequency (RF)circuitry, optical signaling circuity, processing circuitry andsoftware, or some other communication devices. Communication interface1301 may be configured to communicate over wireless links which use airor space as the communication medium. The wireless links can compriseany wireless electromagnetic communication, such as RF communications,VHF communications, UHF communications, microware communications,optical communications (e.g. visible, infrared, or ultraviolet), andcombinations thereof. Communication interface 1301 may be configured touse optical signaling, Internet Protocol (IP), IEEE 802.11 WiFi, amongvarious wireless protocols, communication signaling, or some othercommunication format, including combinations thereof. In someimplementations, communication interface 1301 may communicate with oneor more other satellites in a satellite platform and communicate with aground control system.

Processing circuitry 1305 comprises microprocessor and other circuitrythat retrieves and executes operating software 1307 from memory device1306. Memory device 1306 may include volatile and nonvolatile, removableand non-removable media implemented in any method or technology forstorage of information, such as computer readable instructions, datastructures, program modules, or other data. Memory device 1306 may beimplemented as a single storage device, but may also be implementedacross multiple storage devices or sub-systems. Memory device 1306 maycomprise additional elements, such as a controller to read operatingsoftware 1307. Examples of storage media include random access memory,read only memory, magnetic disks, optical disks, and flash memory, aswell as any combination or variation thereof, or any other type ofstorage media. In some implementations, the storage media may be anon-transitory storage media.

Processing circuitry 1305 is typically mounted on a circuit board thatmay also hold memory device 1306 and portions of communication interface1301 and sensors 1302. Operating software 1307 comprises computerprograms, firmware, or some other form of machine-readable programinstructions. Operating software 1307 includes control module 1308,operating system module 1309, and nodes 1310, although any number ofsoftware modules may provide the same operation. Operating software 1307may further include utilities, drivers, network interfaces,applications, or some other type of software. When executed byprocessing circuitry 1305, operating software 1307 directs processingsystem 1303 to operate computing system 1300 as described herein.

In at least one implementation, virtual nodes 1310 may be deployed tosatellite computing system 1300 that represent full operating systemvirtual machines or containers, wherein each node is configured toprovide a particular application. To run the nodes, operating systemmodule 1309, which may comprise an operating system and/or a hypervisor,may be executed by processing system 1303, wherein operating systemmodule 1309 provides a platform for nodes 1310. In some implementations,in providing the platform, operating system module 1309 may beconfigured with a resource schedule, which allocates processingresources, communication resources, and sensor resources to each node innodes 1310. This allocation of resources, may comprise time divisionallocation of resources, such as providing a first application withaccess to a user sensor for a first time period and providing a secondapplication with access to the same user sensor for a second timeperiod, and may further include physical sharing of resources, such asproviding one or more cores to a first virtual node and providing one ormore secondary cores to a second virtual node.

In addition to executing the applications for each of virtual nodes1310, operating system module 1309 may further provide a platform forstate determination and distribution. This state determination maypermit processing system 1303 to identify states for each of theapplications and share the states with other satellites and the groundcontrol system. The states may include the operational state ofprocesses within each application node, and/or data states for each ofthe application nodes. The states may be used in recovery of the variousapplications executing on satellite computing system 1300, and mayfurther be used in providing enhanced data operations for theapplications. For example, an application executing as a node onsatellite computing system 1300 may communicate data to a secondsatellite node. This satellite node may identify second data, usingsensors on the second satellite, and combine the data from the firstsatellite with the second data to provide a particular operation. Thisoperation may include imaging analysis in some examples, where theapplication can determine whether an object is moving, the type ofobject, the rate of movement in the object, or some other similardetermination based on the combined data.

As an illustrative example, satellite computing system 1300 may use oneor more imaging sensors or an imaging system in sensors 1302 toestablish state information related to imaging data gathered by theimaging sensors. Once identified, the state information may becommunicated to a second satellite device, wherein the second satellitedevice may employ second imaging sensors to modify the state informationwith at least imaging data captured by the second imaging sensors. Thismodification may include positional tracking of at least one underlyingobject of interest, or may include a refining analysis of the stateinformation based on the imaging data captured by the second imagingsensors to act as a recognition process for at least one underlyingobject of interest.

In some examples, in addition to or in place of exchanging the stateinformation to provide additional analysis on the sensor data, the stateinformation may also be used to provide a backup of satellite computingsystem 1300. In particular, the state information may be shared with asecond satellite device permitting the second satellite device toimplement one or more virtual nodes from satellite computing system 1300when a failure is detected. This implementation or establishment of theone or more virtual nodes may occur directly at the satellite receivingthe state information from satellite computing system 1300, or may occuron a third satellite configurable by the satellite receiving the stateinformation from satellite computing system 1300.

Although illustrated in the previous example as providing information toother satellites, it should be understood that satellite computingsystem 1300 may also be configured to receive state information fromother satellites and provide similar operations in accordance with thereceived state information. These operations may include modifying thestate information based on sensors for satellite computing system 1300,or providing backup peering operations based on the state informationprovided from the secondary satellites.

As also illustrated in FIG. 13, satellite computing system 1300 furtherincludes control module 1308, which is used as a flight control systemfor the satellite. In particular, control module 1308, which may operateusing distinct processing circuitry on satellite computing system 1300,may be responsible for power management, logistics, and flight controlof the satellite. In some examples, control module 1308 may receiverequests from nodes 1310 and operating system 1308 to provide data tothe applications on nodes 1310. If a request can be accommodated,without comprising the flight of the satellite, control module 1308 mayprovide the requested data to operating system module 1309 or thecorresponding node. In contrast, if it is determined that theinformation cannot be provided or a flight operation cannot beaccommodated, then control module 1308 may fail to provide the data orthe flight operation.

The included descriptions and figures depict specific implementations toteach those skilled in the art how to make and use the best option. Forthe purpose of teaching inventive principles, some conventional aspectshave been simplified or omitted. Those skilled in the art willappreciate variations from these implementations that fall within thescope of the disclosure. Those skilled in the art will also appreciatethat the features described above can be combined in various ways toform multiple implementations. As a result, the invention is not limitedto the specific implementations described above, but only by the claimsand their equivalents.

What is claimed is:
 1. A satellite system, comprising: satellite devicesin low-earth orbit (LEO) configured to establish a pseudo-geosynchronouscommunication window corresponding to a ground communication system byat least transferring traffic routing instructions from outgoingsatellite devices leaving the pseudo-geosynchronous communication windowfor receipt by target satellite devices entering thepseudo-geosynchronous communication window, wherein the traffic routinginstructions indicate at least a portion of communication traffic amongthe satellite system for routing to the ground communication system; andduring passage within the pseudo-geosynchronous communication window,the target satellite devices each configured to route at least theportion of communications received in the target satellite devices inaccordance with the traffic routing instructions, wherein the satellitedevices route at least the portion of communications for delivery to thetarget satellite devices through zero or more intermediate ones of thesatellite devices.
 2. The satellite system of claim 1, comprising:responsive to detecting exit from the pseudo-geosynchronouscommunication window, the outgoing satellite devices each configured todetermine at least a portion of the traffic routing instructions, anddeliver at least the portion of the traffic routing instructions toassociated target satellite devices.
 3. The satellite system of claim 1,comprising: responsive to detecting entry into the pseudo-geosynchronouscommunication window, the target satellite devices each configured torequest at least a portion of the traffic routing instructions fromassociated outgoing satellite devices.
 4. The satellite system of claim1, comprising: the satellite devices configured to determine entry intoor exit from the pseudo-geosynchronous communication window based atleast on determining overhead proximity to the ground communicationsystem as defined by geographic coordinates.
 5. The satellite system ofclaim 1, comprising: the satellite devices configured to determine entryinto or exit from the pseudo-geosynchronous communication window basedat least on line-of-sight established with the ground communicationsystem.
 6. The satellite system of claim 1, comprising: the satellitedevices configured to determine entry into or exit from thepseudo-geosynchronous communication window based at least on signalstrength of the ground communication system.
 7. The satellite system ofclaim 1, wherein a subset of the satellite devices orbit in a higherorbital distance from others of the satellite devices that pass throughthe pseudo-geosynchronous communication window, and comprising: thesubset of the satellite devices configured to route associatedcommunications for delivery to the ground communication system via theothers of the satellite devices that pass through thepseudo-geosynchronous communication window.
 8. The satellite system ofclaim 1, wherein the traffic routing instructions indicate to route atleast a portion of satellite-to-ground communications received in thetarget satellite devices for delivery through the ground communicationsystem; and wherein the traffic routing instructions further indicate toroute ground-to-satellite communications received from the groundcommunication system in the target satellite devices to one or more ofthe satellite devices.
 9. A method of operating a satellite system,comprising: establishing a pseudo-geosynchronous communication windowamong satellite devices in low-earth orbit (LEO) with relation to aground communication system by at least transferring traffic routinginstructions from outgoing satellite devices leaving thepseudo-geosynchronous communication window for receipt by targetsatellite devices entering the pseudo-geosynchronous communicationwindow, wherein the traffic routing instructions indicate at least aportion of communication traffic among the satellite system for routingto the ground communication system; and during passage within thepseudo-geosynchronous communication window, routing at least the portionof communications received in the target satellite devices in accordancewith the traffic routing instructions, wherein the satellite devicesroute at least the portion of communications for delivery to the targetsatellite devices through zero or more intermediate ones of thesatellite devices.
 10. The method of claim 9, further comprising: in theoutgoing satellite devices, responsive to detecting exit from thepseudo-geosynchronous communication window, determining at least aportion of the traffic routing instructions, and delivering at least theportion of the traffic routing instructions to associated targetsatellite devices.
 11. The method of claim 9, further comprising: in thetarget satellite devices, responsive to detecting entry into thepseudo-geosynchronous communication window, requesting at least aportion of the traffic routing instructions from associated outgoingsatellite devices.
 12. The method of claim 9, further comprising: in thesatellite devices, determining entry into or exit from thepseudo-geosynchronous communication window based at least on overheadproximity to the ground communication system as defined by geographiccoordinates.
 13. The method of claim 9, further comprising: in thesatellite devices, determining entry into or exit from thepseudo-geosynchronous communication window based at least online-of-sight established with the ground communication system.
 14. Themethod of claim 9, further comprising: in the satellite devices,determining entry into or exit from the pseudo-geosynchronouscommunication window based at least on signal strength of the groundcommunication system.
 15. The method of claim 9, wherein a subset of thesatellite devices orbit in a higher orbital distance from others of thesatellite devices that pass through the pseudo-geosynchronouscommunication window, and further comprising: in the subset of thesatellite devices, routing associated communications for delivery to theground communication system via the others of the satellite devices thatpass through the pseudo-geosynchronous window.
 16. The method of claim9, wherein the traffic routing instructions indicate to route at least aportion of satellite-to-ground communications received in the targetsatellite devices through the ground communication system; and whereinthe traffic routing instructions further indicate to routeground-to-satellite communications received in the target satellitedevices from the ground communication system to one or more of thesatellite devices.
 17. A satellite device, comprising: a control systemconfigured to detect overhead proximity to a ground communication systemand establish a pseudo-geosynchronous communication window correspondingto the overhead proximity to the ground communication system while thesatellite device orbits in a low-earth orbit; a processing systemconfigured to execute communication routing tasks with regard to theground communication system in accordance with traffic routinginstructions received from a further satellite device exiting thepseudo-geosynchronous communication window, wherein the traffic routinginstructions indicate at least a portion of communication trafficreceived in the satellite device for routing to the ground communicationsystem, and wherein one or more satellite devices route at least theportion of communications for delivery to the satellite device throughzero or more intermediate satellite devices; and responsive to thecontrol system detecting exit from the pseudo-geosynchronouscommunication window, a communication system configured to transferinformation comprising further traffic routing instructions for deliveryto at least another satellite device for use in execution of furthercommunication routing tasks by the other satellite device during passagethrough the pseudo-geosynchronous communication window.
 18. Thesatellite device of claim 17, comprising: the control system configuredto determine entry into or exit from the pseudo-geosynchronouscommunication window based at least on detected signal strength of theground communication system; during the orbital passage within thepseudo-geosynchronous communication window, the processing systemfurther configured to direct the communication system to route at leastthe portion of communications traffic received from one or moresatellite devices in accordance with corresponding traffic routinginstructions to deliver at least the portion of the communicationstraffic to the ground communication system; and during the orbitalpassage within the pseudo-geosynchronous communication window, theprocessing system further configured to direct the communication systemto route at least a portion of further communications traffic receivedby the satellite device from the ground communication system inaccordance with the corresponding traffic routing instructions todeliver at least the portion of the further communications traffic tothe one or more satellite devices.
 19. A satellite system, comprising:satellite devices in low-earth orbit (LEO) configured to establish apseudo-geosynchronous communication configuration corresponding to aground communication system by at least transferring traffic routinginstructions from outgoing satellite devices leaving thepseudo-geosynchronous window for receipt by target satellite devicesentering the pseudo-geosynchronous window, wherein the traffic routinginstructions at least indicate traffic of the satellite system to routeto the ground communication system; during passage within thepseudo-geosynchronous window, the target satellite devices eachconfigured to route at least a portion of communications received in thetarget satellite devices from the satellite devices for delivery to theground communication system in accordance with the traffic routinginstructions; and a subset of the satellite devices configured to routeassociated communications for delivery to the ground communicationsystem via the target satellite devices, wherein the subset of thesatellite devices orbit in a higher orbital distance than the targetsatellite devices.
 20. A method of operating a satellite system,comprising: establishing a pseudo-geosynchronous communication windowamong satellite devices in low-earth orbit (LEO) with relation to aground communication system by at least transferring traffic routinginstructions from outgoing satellite devices leaving thepseudo-geosynchronous communication window for receipt by targetsatellite devices entering the pseudo-geosynchronous communicationwindow, wherein the traffic routing instructions indicate at least aportion of communication traffic among the satellite system for routingto the ground communication system; during passage within thepseudo-geosynchronous communication window, routing at least the portionof communications received in the target satellite devices in accordancewith the traffic routing instructions; and in a subset of the satellitedevices, routing associated communications for delivery to the groundcommunication system via the target satellite devices, wherein thesubset of the satellite devices orbit in a higher orbital distance thanthe target satellite devices.